PowerEdge Necromancy

Howdy. First consider this as a pre-question question. I've made several failed attempts at re-purposing an old Dell PowerEdge. Its in pieces but everything works, I think. For the time being, I just want it to be an Ubuntu server with a LAMP stack to play with but eventually it will go into a CCNA lab.
My previous attempt ended with me removing the RAID card and booting from one of the HDs. There was this persistent Vista partition it was trying to boot but after I got rid of that it kept trying to boot into Windows Server. I figured what I needed to was just get it to boot my preferred Linux OS, #!. I kept on formatting the drives and installing #! but no dice. I went to the boot order in the BIOS and was totally stumped with the options for SATA and PATA drives, virtual drives, etc, I could only get it to boot one way, and that way would only load Win Server. No GRUB to be found, just that stupid window.
So, since I've found that my usual desktop methodology (burn it all hell, install linux, enjoy) is failing here, what should my general approach be? I'm not even sure whats the right question to ask. Parts list to follow once I dig the machine up.

Thanks

 Im by no means the most tech-savvy person here, and forgive me if this is something youve already tried and/or just a stupid idea, but have you tried or could you, force it to boot a live usb drive with you chosen flavour of linux on it?? 

It would boot that sometimes. tried ubuntu and Parted Magic Live to format the drives. I ran a few of the installers and after it tells me its successful, still won't boot. I think my problem is this BIOS. Its a damn beast. Guess its the difference between consumer and enterprise level gear.